102 
REVIEWS. 
be mentioned under the respective species. It is, however, necessary to record one 
instance which throws some light upon the economy of the genus. Some years 
ago, in the month of June, I met with a large colony of Eucera longicornis, and 
observed great numbers of Nomada sexfasciata flying about amongst the bees, and 
occasionally entering into and issuing from their burrows. In the beginning of 
April of the following year I visited the locality for the purpose of obtaining males 
of the Nomada, as very few were found when the colony was first discovered ; the 
cells of Eucera were found at about the depth of eight inches in a stiff clayey soil; of 
these a considerable number were obtained; on examination, many of the bees 
were found to be in the pupa state, some far advanced towards their perfect con¬ 
dition, others still larvse ; on opening one cell, it was found to contain two speci¬ 
mens of Nomada sexfasciata. Since the former visit I have, on several occasions, 
obtained the cells of Eucera, and have endeavoured to find the larva of Nomada, 
but in vain; perfect individuals of N. sexfasciata have been found in the cells of 
Eucera on several occasions, usually two in each cell, and once a pair of N. 
alternata.” 
Of Epeolus variegatus , again (the only indigenous species of this genus), 
the author informs us— 
“ This pretty little bee is very abundant in many parts of Kent, Surrey, and 
Hampshire; it is also met with at Southend, in Essex; it is, however, local; 
wherever Colletes Daviesana is found, Epeolus, its parasite, is to be met with; it 
has been found in the burrows of that bee. It usually appears early in July ; the 
males pass a great portion of their time reposing in flowers, particularly on the 
heads of the ragwort; they are also partial to the mouse-ear hawkweed, and may 
frequently be found enclosed in the petals of the flowers; the habit of this bee is 
very sluggish ; they are easily captured by hand ; their sting is very acute.” 
The preceding extracts may give some idea of the Natural History 
touches which are interspersed among the descriptive portions of the 
volume, so abundantly, that there is scarcely one, except the rarest species, 
with regard to which Mr. Smith has not some particulars to communicate. 
Having drawn so freely already from the source, we will venture to extract 
only one more bit of biography before we proceed to the technical details, 
indispensable in reviewing a work of such scientific character— 
“If I were asked which genus of bees would afford the most abundant materials 
for an essay on the diversity of instinct, I should, without hesitation, point out the 
genus Osmia. I propose to notice in this place all that has occurred to me during 
an attentive observation of their economy lor the last twenty years. Mr. Kirby, 
in the ‘ Monographia Apum Angliaa,’ has quoted the history of Reaumur’s mason- 
bee, which, although not included in the present genus, is still so nearly allied that 
its history might be taken as a parallel to that of Osmia ; but as it is not a British 
species, I merely allude to it to call attention to the highly-interesting history 
given by Reaumur of its economy. The most abundant species is Osmia bicornis ; 
its economy is varied by circumstances; in hilly country, or at the sea-side, it 
chooses the sunny side of cliffs or sandy banks, in which to form its burrows ; but 
in cultivated districts, particularly if the soil be clayey, it selects a decaying tree, 
preferring the stump of an old willow } it lays up a store of pollen and honey for 
the larvas, which, when full-grown, spin a tough, dark brown cocoon, in which 
they remain in the larva state until the autumn, when the majority change to 
pupae, and soon arrive at their perfect condition; many, however, pass the winter 
in the larva state. In attempting to account for so remarkable a circumstance, 
all must be conjecture, but it is not of unfrequent occurrence; this species, also, 
frequently makes its burrows in the mortar of old walls. Osmia leucomelana may 
be observed availing itself of a most admirable, and almost ready, adaptation for a 
